A.J.'s TV has something called a Parental Block, which prevents him from watching any non-educational programs (as well as any animal violence on the educational programs).
This episode marks the first appearance of Chester's mother, yet she was only seen in a photo picture.
When Timmy is trying to fake a dog attack, he doesn't realize that Cosmo and Wanda accidentally left and were replaced with real junkyard dogs. He doesn't realize this until he's actually attacked, despite the real junkyard dogs obviously being a different color than Cosmo and Wanda.
This gag is repeated in Spring Break-Up, an episode with a slightly similar premise.